Solenoid bobbin winders



Feb. 14, 1967 J. w. cRAwFoRD SOLENOID BOBBIN WINDERS 2 Sheets-Sheet lFiled Feb. 19, 1964 INVENTOR WITNESS United States Patent O 3,393,802SOLEND B01531151 WENDERS John W. Crawford, Neptune, NJ., assigner tor111e Singer Company, New York, N.Y., a corporation of New Jersey FiledFeb. 19, 1964, Ser. No. 345,892 3 Claims. (Cl. 2112-184) This inventionrelates to lock stitch sewing machines of the type including mechanismfor winding thread on the bobbin in place in the loop taker, and moreparticularly, to a novel and improved means for operating the bobbinwinding mechanism.

It is an object of this invention to provide a solenoid carried by thesewing machine and operatively connected so as to effect shift of thebobbin winding mechanism into operative position.

In the operation of a mechanism for winding thread on a bobbin in placein the sewing machine loop taker during normal interrelated movements ofthe needle and loop taker as are required for the formation of stitches,a problem exists in -providing a means for preventing or deerringoverwinding of the bobbin, which overwinding can occasion jamming of theloop taker and breakage of parts. Heretofore, it has been known to useswitching mechanism responsive to the sensing of fully wound conditionof the bobbin for terminating the winding operation. This approach tothe problem, however, requires that delicate switching components beprovided and that a highly critical arrangement of these switchingcomponents be maintained. It has also been known heretofore to provide ameans responsive to the sensing of fully wound condition of the bobbinfor overloading the sewing machine drive motor to deter overwinding ofthe bobbin, but this approach to the problem raises the possibility ofdamage to the relatively costly sewing machine drive motor. l

lt is another object of the present invention to provide a novel meansfor actuating a bobbin winding mechanism in place in a sewing machineloop taker which will function to signal the onset of bobbin overwindingwithout switching components or the like and without imposing anoverload condition on the sewing machine drive motor.

In accordance with this invention, the shift of the bobbin windingmechanism of the sewing machine into operative bobbin winding positionis accomplished by an alternating current operated solenoid which may beenergized by the same power supply as is used to drive the conventionalsewing machine drive motor.

The solenoid is arranged such that its armature seats or bottoms in theoperative bobbin winding position of the bobbin winding mechanism whenthe bobbin is not fully wound, By arranging the device for sensing thefully wound condition of the bobbin so as to effect a shift of thesolenoid armature slightly out of seated or bottomed position, the humincident to the alternating current actuated solenoid operation ismaterially increased, thus providing an audible signal useful to deteroverwinding of the bobbin.

It lis also an object of this invention to provide a novel controlcircuit for the solenoid which will simultaneously actuate the bobbinwinding mechanism solenoid and the sewing machine drive motor incomplete independence from the conventional sewing machine drive motorcontrol. This novel control circuit arrangement is advantageous in thatit provides for the termination of the drive to the sewing machinemechanism upon termination of the bobbin winding operation and thusobviates sudden unexpected initiation of stitch forming operations.Moreover, this novel control arrangement is also advantageous in that itprovides for preselection of the operating con- Patented Feb. 14, 1967dition of the sewing machine drive motor to an optimum value for bobbinwinding during the bobbin winding operation.

With the above and additional objects and advantages in View as willhereinafter appear, this invention comprises the devices, combinations,and arrangements of parts hereinafter described and illustrated in theaccompanying drawings in which:

FIG. l represents a vertical cross sectional view of a sewing machinehaving this invention applied thereto,

FIG. 2 represents an enlarged vertical cross sectional view of the looptaker of the sewing machine of FIG. l together with the bobbin windingmechanism actuating solenoid with the solenoid turned bodily at rightangles to the position shown in FIG. 1 more clearly to illustrate therelationship of parts and with the parts illustrated in the bobbinwinding position and the bobbin not fully wound,

FIG. 3 represents a vertical cross sectional View of the loop taker andsolenoid similar to that of FIG. 2 but with the parts illustrated in thebobbin winding position with the bobbin fully wound, and

FIG. 4 is a wiring diagram illustrating the control circuit for thebobbin winding mechanism solenoid and for the sewing machine drivemotor.

Referring to the drawings, this invention is illustrated as applied to asewing machine of the type including a provision for windingreplenishment thread on the bobbin in place in the loop taker such as isdisclosed in the United States patent of S. l. Ketterer, No. 3,115,855,December 31, 1963, to which reference may be had. The sewing machineincludes a frame having a bed 11, a standard 12 rising from the bed, anda bracket arm 13 extending from the standard and overhanging the bed.Journaled in the bracket arm is a main drive shaft 14 to which issecured a handwheel 15 and a worm wheel 16 which meshes with a worm 17fast on the drive shaft of an electric motor 18 which may be housedwithin the standard as illustrated in FIG. 1. A crank 19 carried on themain drive shaft serves by way of a drive link 20 to reciprocate aneedle bar 21 which is journaled for endwise movement in the bracket armand carries at its lower extremity a needle 22. The crank 19 also servesto impart oscillatory motion to a needle thread take up member 23.Iournaled in the bed 11 in a position to c0- operate with the needle inthe formation of stitches is a loop taker indicated generally as 24. Theloop taker is fast on a hollow loop taker shaft which is drivinglyconnected by miter gears 2e to a bed shaft 27 connected in turn by mitergears 28 and 29 and a vertical shaft 30 in the standard to the maindrive shaft 14. It will be understood that the main drive shaft 14 andthe gear drive 26, 28 and 29 constitute an actuating mechanism forimparting interrelated motion to the needle and loop taker as isrequired for the formation of lock stitches.

Referring particularly to FiGS. 2 and 3, the loop taker 24 is formedwith a cup-shaped body portion 4@ of which the rim is formed with anannular bearing rib 42 ernbraced by an annular raceway 43 formed in abobbin case 44 which is constrained from rotation with the loop takerbody portion as is well known in sewing machine art. Resting upon anannular shoulder 45 formed Ion the bobbin case is Ithe upper flange 45of a thread carrying bobbin 47 which is formed with a lower antge 48having an annular groove 49 formed therein, in which groove a drivingabutment 50 is formed. The bobbin 47 is constrained against the bobbincase shoulder 45 by a springloaded lever 51 which is carried on thebobbin case 44 and is formed with a spherical protuberance 52 seated ina depression 53 in the upper ange 46 on the bobbin.

For winding replenishment thread on the bobbin in place in the looptaker while the needle 4and loop taker partake of normal interrelatedmotions as are required f-or the formation `of lock stitches, a bobbinwinding member 60 is provided within the cup-shaped body portion of theloop taker and beneath the bobbin. The bobbin winding member 60 is faston a rod 61 which is slidable endwise in the hollow loop taker shaft 25.A bracket 62 which is fast on the rod 61 beneath the loop taker shaft isformed with an upturned lug 63 which enters an aperture 64 in that mitergear of the miter gear set 26 which is fast on the loop taker shaft, sothat the bobbin winding member 60 is constrained to rotate with the looptaker. The bobbin winding member 60 is formed with an upwardly extendingflange 65 which serves to embrace the lower flange i8 of the bobbin whenthe bobbin winding member and the rod 6,1 are shifted upwardly asillustrated in FIGS. 2 and 3. In addition, the bobbin winding member 60'includes a driving lug 66 which enters the annular groove 49 in thelower flange 48 of the bobbin when the bobbin winding member 60 israised, and thereby assumes a bobbin driving relationship with theabutment formed with the annular groove 49. As explained more completelyin the above referenced United States Patent No. 3,115,855 to whichreference may be had, the bobbin winding member 60, when raised into theposition illustrated in FIGS. 2 or 3, serves to effect winding ofreplenishment thread on the bobbin by virtue of the ange 65 on thebobbin winding member which deflects thread being manipulated by theloop taker into the space between the bobbin flanges, and by virtue ofthe driving relationship between the driving lug 66 and the abutment 50which serve to rotate the bobbin with the loop taker, thus to wind onthe bobbin a thread extending from the needle 22. When the tbobbinwinding member is lowered into the position illustrated in FIG. l inwhich the flange of the bobbin winding member is completely beneath thelower flange 48 of the bobbin. needle thread loops seized andmanipulated between loop taker beak 41 are free to pass beneath andabout the bobbin, thus to concatenate with thread wound on the bobbintto form lock stitches.

For effecting elevation of the bobbin winding member 60 into operativebobbin winding position, a solenoid indicated generally at 70 isemployed in this invention. The solenoid includes a core '71 which maybe of conventional laminated construction and is secured as byfastenings 72 to a casing '73. An Ioutturned lug 74 on the solenoidcasing is slotted as at 75 to accommodate a fastening screw 76 by whichthe solenoid core may be secured to the sewing machine bed 11 withprovision for limited adjustment `of the position of the solenoid in adirection axially of the loop taker. Articulated relatively to thearmature core as by a pivot pin 77 passing through one pole 78 tof thesolenoid core is an armature 7) which is thus shiftably supported formovement into and out of engagement with the other pole 80 of thearmature core 71. A solenoid coil 81 wound on the core 71 when energizedserves to draw the armature 79 into seated or bottomed relation againstthe pole 80 of the armature core. A shading coil 82 may be provided onthe pole 80 of the armature core to provide for a continuity of magneticflux when the solenoid coil is energized by an alternating current so asto minimize the vibration of the armature relatively to the solenoidcore when the armature is seated or bottomed against the pole 80 of thesolenoid core.

The solenoid 70, which is thus adapted for alternating currentoperation, is formed with an extended armature extremity which isapertured as at 91 to embrace the lower extremity of the bobbin windingmember rod 61 and is preferably constrained relatively to the rod 6-1ybetween spaced nuts 92 threaded thereon. The `armature extension 90 mayalso be slightly crowned as at 93 so that the pivotal motion of thearmature will not conflict with the translatory endwise sliding movementof the rod 61. The solenoid fastening screw 76 in the slotted lug 74 4-of the solenoid casing may be used to secure the solenoid to the sewingmachine bed in a selected position in which the solenoid armature 79will occupy a seated or bottomed position against the solenoid core pole80 when the solenoid is energized and the bobbin winding member israised into operative bobbin winding lengagement with the bobbin asillustrated in FIG. 2 and the bobbin is not fully wound with thread. Inthis position of the parts, as the bobbin thread repleni'shing processbegins and while the bobbin is less than fully wound, the solenoid 70will operate with a minimum of vibration or hum.

Pivoted on a pin set into the bobbin case 44 is a bobbin thread sensingmember 101 having a thread engaging shoe 102 extending between the anges46 and 48 of the bobbin. The bobbin thread sensing member 101 also isformed with an inclined cam surface 103 disposed for engagement with theupturned flange 65 of the bobbin winding member when the bobbin threadsensing member is forced outward by engagement of the thread engagingshoe 102 with thread that is being wound on the bobbin. As illustratedin FIG. 3, the cam surface 103 is positioned relatively to the threadengaging shoe 102 so as to engage and depress the ange 65 of the bobbinwinding member as the thread approaches the fully wound condition on thebobbin 47. The rod 61 associated with the bobbin Winding member will, inbeing depressed with t-he bobbin winding member 60, force the solenoidarmature 79 slightly out of seat or bottomed relation against the`armature core pole 80 as illustrated in FIG. 3 of the drawing in whichcondition the inuence of the shading coil 82 of the solenoid will bematerially decreased resulting in a noticeable increase in the vibrationand hum developed by the alternating current actuation of the solenoid.This hum is of such a noticeable nature as to serve as a persistentaudible signal to the sewing machine operator that the -bobbin is infully wound condition. Furthermore, it is pointed out that the inuenceof the Ibobbin thread sensing member in camming the bobbin windingmember 60, the rod 61, and the solenoid armature 79 downwardly inresponse to the fully wound condition of the bobbin does not materiallyinuence the driving force required of the sewing machine actuatingmechanism and therefore, does not impose any appreciable overloadcondition upon the sewing machine drive motor 18.

Referring to FIG. 1, the wiring in the electrical circuit for both thesewing machine drive motor 18 and for the solenoid 70 is associated inthe sewing machine with a three pin receptical which is adapted, as isconventional in the sewing art, to accommodate a plug 111 to which isdirected conductors 112 and 113 to a source of power supply indicated at114 and also a conductor 115 to a foot controller 116. Referring to thecircuit diagram illustrated in FIG. 4, the foot cont-roller 116, whichis of the type including an on-oif switch and a rheostat for controllingthe sewing machine drive `motor speed at the will of the sewing machineoperator is connected by a conductor 119 to the conductor 112 and iswired in series with the sewing machine drive motor 18 by the conductors118 and 119 within the sewing machine. Indicated at 120 is a doublecircuit push button switch which is preferably spring loaded into thenormally open position and must be held closed by the Operator of thesewing machine. The switch 120 is connected by the conductor 121 to theconductor 112 and controls simultaneously two circuits across theconductors 112 and 113 from the power source. The sewing machine drivemotor 18 is connected into one of the circuits controlled by the switch120 by a conductor 122 in which circuit a motor speed controllingresistor 123 may be included so as to provide for a preselected motorspeed when 'the switch 120 is closed and the foot controller 116 is notoperated. The other circuit controlled by the switch 120 serves by wayof conductors 124 and 125 to connect the solenoid coil 81 across theconductors 112 from the power source 113. With this arrangement closureof the push button switch 120 by the sewing machine operator serves toenergize simultanously the sewing machine drive motor 1S and thesolenoid 70 which initiates a bobbin winding operation. When an audiblesignal is provided to the sewing machine yoperator by virtue of the humproduced -by the solenoid when the fully wound condition of the bobbinis sensed, release or" the push button switch 120 by the operator willserve to terminate the bobbin winding operation and to deenergize thesewing machine drive motor so that the sewing machine will not suddenlyrevert to normal sewing operation. Thereafter, the motor 18 may beenergized to control the sewing machine during sewing by the use of thefoot controller 116.

Having set forth the nature of this invention, what is claimed hereinis:

1. In a lock stitch sewing machine having a frame, a thread carryingneedle endwise reciprocable in said frame, a circularly moving looptaker journaled in said frame, a thread carrying bobbin journaled withinsaid loop taker, act-uating mechanism in said frame operativelyconnecting said needle and said loop taker for interrelated movements asare required for the formation of lock stitches, a bobbin Winding membercarried within said loop taker, and means shiftably supporting saidbobbin winding member for movement axially of said loop taker into andout of operative engagement with said bobbin, means for at Will shiftingsaid bobbin winding member axially of said loop taker into operativeengagement with said bobbin comprising a solenoid including a coreprovided with a solenoid coil, an armature shiftably supportedrelatively to said core, means operatively connecting said armature tosaid bobbin winding member, and means securing said solenoid core tosaid sewing machine frame with said solenoid armature in seated relationagainst said solenoid core in the operative engaged position of saidbobbin winding member with said bobbin.

2. In a lock stitch sewing machine having a trame, a thread carryingneedle endwise reciprocable in said frame, a circularly moving looptaker iournaled in said frame, a thread carrying bobbin journaled withinsaid loop taker, actuating mechanism in said frame operatively`connecting said needle and said loop taker for interrelated movementsas are required for the formation of lock stitches, a vbobbin Windingmember carried within said loop taker, and means shiftably supportingsaid bobbin winding member for movement axially of said loop taker intoand out of operative engagement with said bobbin, the combination ofmeans for shifting said bobbin winding member axially of said loop takerinto operative engagement with said bobbin comprising la solenoidincluding a core provided with a solenoid coil, an armature shiftablysupported relatively to said core, means operatively connecting saidarmature to said bobbin Winding member, and means securing said solenoidcore to said sewing machine frame with said solenoid armature in seatedrelation against said solenoid core in the operative engaged position ofsaid bobbin winding member with said bobbin, a bobbin thread sensingmember shiftably supported in said loop taker in position for movementunder the inliuence of a predetermined quantity of thread Wound on saidbobbin, and means operatively connecting said bobbin thread sensingmember with said solenoid armature for eiecting a shift of said solenoidarmature out of said seated relation against said solenoid core uponmovement of said bobbin thread sensing member in response to saidpredetermined quantity of thread Wound on said bobbin.

3. In a lock stitch sewing machine having a frame, a thread carryingneedle endwise reciprocable in said frame, a circularly moving looptaker journaled in said frame, a thread carrying bobbin journaled withinsaid loop taker, actuating mechanism in said frame operativelyconnecting said needle and said loop taker for interrelated movements asare required for the formation of lock stitches, an electric motordrivingly connected to said actuating mechanism, a bobbin winding membercarried within said loop taker and means shiftably supporting saidbobbin winding member for movement axially of said loop taker into andout of operative engagement with said bobbin, means for at will shiftingsaid bobbin Winding member axially of said loop taker into operativeengagement with said bobbin comprising a solenoid carried by said sewingmachine frame and including a core provided with a solenoid coil, anarmature shiftably supported relatively to said core, means operativelyconnecting said armature to said bobbin winding member, and a controlcircuit for said electric motor and said solenoid coil from a commonsource of electrical supply comprising a ti-rst switch means operativelyconnecting only said electric motor to said source of supply, and asecond switch means operatively connecting both said electric motor andsaid solenoid coil simultaneously to said source of supply.

References Cited by the Examiner UNITED STATES PATENTS 1,029,335 6/1912Baker 112-186 1,794,255 2/1931 Stephenson 112--181 2,255,152 9/ 1941Colegrove 242-22 3,156,429 11/1964 Jones 242-865 3,138,127 6/1964Ketterer 112-184 3,154,035 10/1964 Edwards et al i12-184 JORDANFRANKLIN, Primary Examiner.

H. H. HUNTER, Assistant Examiner.

1. IN A LOCK STITCH SEWING MACHINE HAVING A FRAME, A THREAD CARRYINGNEEDLE ENDWISE RECIPROCABLE IN SAID FRAME, A CIRCULARLY MOVING LOOPTAKER JOURNALED IN SAID FRAME, A THREAD CARRYING BOBBIN JOURNALED WITHINSAID LOOP TAKER, ACTUATING MECHANISM IN SAID FRAME OPERATIVELYCONNECTING SAID NEEDLE AND SAID LOOP TAKER FOR INTERRELATED MOVEMENTS ASARE REQUIRED FOR THE FORMATION OF LOCK STITCHES, A BOBBIN WINDING MEMBERCARRIED WITHIN SAID LOOP TAKER, AND MEANS SHIFTABLY SUPPORTING SAIDBOBBIN WINDING MEMBER FOR MOVEMENT AXIALLY OF SAID LOOP TAKER INTO ANDOUT OF OPERATIVE ENGAGEMENT WITH SAID BOBBIN, MEANS AND OUT OF OPERATIVEENGAGEMENT WITH SAID BOBBIN, AXIALLY OF SAID LOOP TAKER INTO OPERATIVEENGAGEMENT WITH SAID BOBBIN COMPRISING A SOLENOID INCLUDING A COREPROVIDED WITH A SOLENOID COIL, AN ARMATURE SHIFTABLY SUPPORTEDRELATIVELY TO SAID CORE, MEANS OPERATIVELY CONNECTING SAID ARMATURE TOSAID BOBBIN WINDING MEMBER, AND MEANS SECURING SAID SOLENOID CORE TOSAID SEWING MACHINE FRAME WITH SAID SOLENOID ARMATURE IN SEATED RELATIONAGAINST SAID SOLENOID CORE IN THE OPERATIVE ENGAGED POSITION OF SAIDBOBBIN WINDING MEMBER WITH SAID BOBBIN.